Glass-making furnace.



L. A. THORNBURG. I

GLASS MAKING FUMIAGL'.

APPLICATION FILED NOV. 20. 1909. REHEWBD JUNE 14, 1913- mm; a. 5

Pafientexi F8112, 1915.

45 off the cylinder is linder.

- the principal chamber UNTTED STATES PATENT @TTTQEO LINCOLN A. THORNBURG, OF ARNOLD, PENNSYLVANIA ASSIGNOR TO AMERICAN WINDOW GLASS MACHINE COMPANY, OF 'PITTSBURGH,'PENNSYI|VANIA, A COR- V PORATION OF NEW JERSEY.

GLASS-MAKING FURNACE.

Specification of Letters Patent.

Pjatentedheb. 2, 1915.

Application filed November 20, 1909, Serial No. 529,040. Renewed June 14, 1913. Serial No. 773,760.

BURG, a citizen of the United States, resid-- ing at Arnold, in the State ofvPennsylvania,

' have invented certain new and useful Improvements in Glass-Making Furnaces, of which the following is a specification.

My invention relates especially to the art of drawing glass cylinders for the purpose of making window glass and the like and is particularly concerned with the provision of an improved receptacle for containing glass being drawn, and other means to improve the quality, uniformity, and facility of production of cylinders or other hollow articles, the primary objects being to control the molten glass and temperature conditions, and facilitate the clearing outv of residue left after a cylinder is cut off.

I have illustrated the invention in one form in the accompanying drawing, in which I Figure 1 is a central vertical section through an improved forehearth embodying myinvention; Fig. 2,is a vertical section on the line 2-of Fig. 1, and Fig. 3 is a plan section on the level of line 3 of Fig. l. 1

It .is well known in this art that there are certain advantages in drawing from a shallow body of glass, and the most successful practice has been the drawing from shallow pots also that it is difficult to control-the temperature of the body of glass also that it is-necessary to quickly, remove the cold residue left after the cutting off of a cyl- In my invention, I draw out of a forehearth in, direct communication with the Whole body of the glass in the melting tank, but I arrange" it that the glass at the drawing point is of comparatively shallow depth,

is securely confined against movement, and is sufiicientlycoolfor rapid drawlng; meanwhile, the temperature conditions are kept uniform and the residue left after cutting immediately removed. and melted back'at another place and without interrupting the drawing operations. 4 Thus in the drawing, 4: represents part 'of-alarge melting tank, and 5 is a forehearth, pro eeting therefrom and having its mouth d vided by partition 6. This forehearth also has a further outwardextension? separated from by means of a clay wheel on shaft 16 "in the framework 17, the

' the damper 8, and forming the drawing chamher. It is covered by a hollow top stone 9 and its bottom is somewhat higher than the bottom of the melting back chamber 5, which has its bottom on the same level with that of the tank. On the bottom of the drawing chamber centrally of the drawing position I place a boss 11 for the purpose of chilling the lass in the center and also an annular fixed ring 12 on the bottom to keep the flow of glass more steady and the temperature uniform. Directly above this annular boss, I-use a floatingring 13 surrounding the opening 14 ini'the top stone 9 through which the cylinder is drawn. Several of these rings are provided, so that after drawing the cylinder out of one of them and cutting off the-residue therein, the ring may be pushed out-into the melting back chamber 5 and a new ring introduced into the drawing chamber, thus immediately removing all cold glass and making ready for the next draw. t

The top stone 9 is hinged to the forehearth and bv means. of a chain 15 and topstone can be raised by means of a handle 18. At the same time by a similar chain 19 the stop door'or damper 8 is also lifted simultaneously, both these parts being balanced by counterweights 20 also hung from shaft 16. Y

The forehearth 5 may be specially heated by bnrner flues 21-, coiiperating with the downtake fines The drawing chamber has practically a semicircular front and is covered by a double wall leaving a heat insulating chamberv 23, and in this I may provide extra heat by burners 24; and downta-ke flue 25. preferably deeper at the front side next tothe double wall, and itis also separated from't'he. melting back chamber by a breaker 8 across the mouth under the stop door 8 The drawing chamber? is alsd All these-features are forv more perfectly preserving a. uniform temperature during draws The hollow topstone 9 may be kept cool by water circulating through pipes .26. Thisforehearth'is to be used withany convenient drawing mechanism, such as that, shown in my co-pending application, No. 529,089, filed November will be understood that'in the operation the top stone 9 and damper 8 are raised, a ring 20th, 1909, and it 7 13 is drawn into place over the annular boss 7 lifting upwardly.

1-2 andthe topstone-and damper lowered, the top stone being in contact and holding the ring 13 in place, and the drawing proceeds as usual by di ping in the bait and X ter the cylinder is drawn and cut oil, the top stone and damper being raised, the ring 13 containing the 'residue of glass ispushed outward into the melting back chamber on -one side'of the partition 6, and a new ring 13 is immedi- V partition and I Otherwise it will be understood that I may 15.

'ately drawnin from the otherside of this the process is repeated.

use floatingipots instead of the rings 13 manipulatin them in the same'way. The melting-'bac thus takes place in the hot part-of'the melting furnace or forehearth and not inthe drawingchamber, and the re- ,0

nioval oftlie old ring and cold glass automatically; 'draws in fresh glass, the temperature conditions being the same not only' for each draw buf'throughout the draw, and

-' extension in communication with the fur- .nace tank,:said1cl 1amber having on its bot.- tom a :centralfchillmg boss, and-abOttom itlbeing possible to draw as long a cylinder F25 asdesired; the various f advantages of the device will readily" occur tothose familiar the art. a

;.;.Having thus descr bed my invention and illustrated its-use, I claim:

l. A furnace having a'drawing chamber ringisl lll'bundjng idb a y. -d'escribedp'g 1 3. .A furnacehayin horizontal drawingcha nber ex'tenslon in communication with tank, said chambihhaving '0 1 i' its'bottoni a central chilling boss, a ring surrounding said--boss,- toget her with a fid'at-.

, ing -memher arranged. to; be brought into positionover said boss, and a movable top.- A signed my name in. the.

1 stoneforsaid chamber, substantially as described.'

' Afglas's having a forehearth, and the ,forehearth'having a drawing chainbeer extension; a vertically movable damper for controlling the communication between described.

I *Witne'sss: the forehearth and the drawi'ngchamber,:a vertically mo'yable 'topstone for the draw ing chamber, and means for simultaneously.

moving the damper and the topstone,"to-

gather with means for cooling the topstone,

substa'ntially as described. Y 5. A glass furnace having a 'forehearth,

the forehearth having ahorizontal drawing extension hearth, said hearth extension be: ing of less depth than the forehearth properbut of increasing depth. towardits outer end; substantially as described.

6. A glass furnace-having a? fore hearth,

the forehearthhaving'a horizontal drawing extension hearth, said hearth extension be.- ing of less depth than theforehe'arth proper but of increasingdepth toward its outer end, and the-bottom of the drawing extenf.

sion having glass chilling means rojecting'.

scribed. I

7. A glass furnace having a forehearth,

' the 'forehearth having a horizontal drawing extension hearth, said hearth extension bee '75 upwardly therefrom;..substantiay" as de- 1 ing of, less depth than the forehearth proper fbut of increasing depth toward its outer end, the front wall of said extension having a heating chamber therein I substantially. 8. A glass-furnace af -orehearth,

the forehearth having a horizontalrdrawing extension hearth, said hearth extension being of less; depth than the foreheartli proper but of 1 increasing depth toward ,its outer, end, and the bottonr of the drawing extension having. glass chilling meansprojecting sition .over the chilling means; substantially; asdescribed. j-

.9. A glass furnacefhaving a. horizontaldrawing extension, said -.exten'sio n being. of

incr asing depth-toward te end; Sub-Ill:

. f .g 'd n x stantially as described. -10. A-glass'furnamha u wardly therefrom, .toge'ther witha floating 'memherarran'gd to he brought linto .p o'-.

tension or forehearth at one end, said-exten vide for a gradually increasing depth of the .sion having its bottom wall. slanting'down-.v Iwardly toward its-outer endto thereby pro-pf,

glass containingchamber of'tlie tension, substantially as described. a a In testimony whereof; I have hereunder presenceofthe two subscribed W tnesses. i J

' CLARA Tnonxn'tnze, CHAS. -S. Lerner. 

